This invention relates to a method and an apparatus for setting up a concrete form for the forming of a concrete member therein. This invention also relates to a method and apparatus for continuously supplying the concrete form with concrete.
Precast and prestressed concrete structural members are typically formed by pouring concrete into a form which molds the concrete into a desired shape for the structural member. Conventional shapes for the structural members include those having a rectangular, single "T" or double "T" shaped cross-section. These concrete members are thus accordingly known in the industry as flat slabs or panels and "single-tee" and "double-tee" beams. A single-tee beam includes a horizontal deck portion having a leg or stem portion which extends vertically downwardly from a central area of the deck portion. A double-tee beam is similar to the single-tee beam except that it includes two legs or stem portions extending vertically downward from the deck portion.
A common application of such beams is in the formation of roofing and flooring sections of parking garages for cars, and for other portions of buildings in which the application of the beams would be appropriate. The beams are placed side-by-side, and may be attached to one another through the welding together of steel weld assemblies, which include bars embedded in the deck portion of the beam and which are provided on the edges of the deck portions of the beams. Alternately, weld plates such as those disclosed in co-pending U.S. Pat. Application Ser. No. 06/887,519, filed July 21, 1986, now U.S. Pat. No. 4,724,649, entitled, "Side Weld Plate", could be provided on the sides of the deck portions for welding to one another, which would allow the deck portions to be maintained in a secure, side-by-side relationship.
Although the present invention could be used in connection with the forming of a variety of shapes of concrete members, it is discussed for illustrative purposes as being used primarily in the forming of double-tee beams. A conventional double-tee beam form for forming elongated concrete double-tee beams is normally constructed of steel and includes horizontal surfaces for forming the deck portions of the beam and downwardly and inwardly sloped surfaces depending from the horizontal surfaces of the form for forming the leg or stem sections of the double-tee beam. The stem portion of the double-tee beam formed must slope generally downwardly and inwardly to permit the molded double-tee beam to be readily removed from the form upon hardening.
Prior to the pouring of the concrete into the form, tensioned wire cable strands are provided the lengths of the stem forming portions of the concrete form. These tensioned strands are typically depressed and held down to the bottom surface of the stem forming portion of the concrete form and become embedded in the double-tee beam for strengthening it. Sheets of reinforcing material such as wire mesh or wire fabric are also provided in areas of the stem portions and on the horizontal surfaces of the concrete form prior to the pouring of the concrete therein. Upon the pouring of the concrete into the form, the strands, which are tensioned, and the sheets of wire fabric are embedded into the concrete member for prestressing it to add increased strength to the beam once it is removed from the form.
A typical concrete form in which double-tee beams are poured may be up to several hundred feet long. Because the required length of the beams to be poured are generally much less than the length of the form, the form is used to pour several beams at a time, the form being divided by dividing members commonly referred to as bulkheads. The bulkheads are typically steel and may weigh in the upwards of several hundred pounds. Bulkheads have a cross-sectional shape generally similar to that of the cross-section of the beam which is to be formed and are inserted into the concrete form at appropriate places for dividing the concrete form into several compartments for forming several beams at a time. The bulkheads include slotted members which extend into the stem portions of the concrete form. Provided in the slotted members are strand dividers which serve to support and separate the tensioned strands in the stem portions of the concrete form. Because of their weight, the placement and removal of the bulkheads from the concrete form are commonly performed using a crane, winch mechanism, or the like.
After the pouring of the concrete into the form, a tarpaulin or cover is generally provided to cover the deck portion of the beam during curing, which otherwise would be exposed to the environment. Prior to removing the beams from the form, the cover is removed.
A machine is presently manufactured for use in the setting up of a concrete form in which double-tee beams are to be poured. The machine is the "UTILITY KART", manufactured by Mixer Systems, Inc. of Menomonee Falls, Wis. The machine is hydraulically powered by a gas powered engine and includes a cover reel for unrolling, rolling up, and storing a concrete form cover as the machine passes over the concrete form. A lift is also provided on the machine for removing and setting bulkheads into the concrete form. The hydraulic system of the machine depresses the strands into the stem portions of the concrete form prior to the pouring of concrete. After pouring of the concrete, hydraulically powered screeds are used for settling and removing air pockets from the concrete. After screeding of the concrete, the cover reel is used to replace the cover thereon.
After the concrete beams have been removed from the elongated form, and before the pouring of concrete into the form for the next beams, the form must be cleaned. This can be done manually, or, as disclosed in U.S. Pat. No. 4,578,837, granted to Baer, entitled, "Apparatus for Cleaning Tee Forms", the stem portions of the concrete form can be cleaned with a rotating brush assembly which is powered by an engine. The engine and brush assembly are movable along the concrete form for cleaning the stem portions along the length thereof. U.S. Pat. No. 3,562,832, granted to Rickard, discloses the use of powered horizontal brushes for cleaning the horizontal surfaces of the concrete form and powered conical brushes which are for cleaning the sides of the stem portions of the form as the machine is moved along the form.
After cleaning of the concrete form and prior to the pouring of the concrete, the surfaces of the concrete form are generally provided with a coating of release or form oil which lubricates the surfaces of the form for allowing easier removal of the concrete beam from the form after hardening. The application of the form oil to the concrete form is often applied by the use of hand held sprayers.
After setting up of the concrete form with the bulkheads, tensioned strands, deck wire, stem reinforcing material, weldment fixtures, etc., the concrete form is ready for receiving the concrete. The supplying of concrete to the form is generally done with a series of concrete pourings, with the concrete then being spread and compacted into the form in some manner. The deck portion of the beam is screeded for providing it with a suitable surface finish.
Various devices exist for dispensing concrete from a moving structure. U.S. Pat. No. 806,371, granted to Siegwart, entitled, "Machine for Manufacturing Hollow Artificial Stone Beams or Girders", discloses a device having cement supply hoppers attached to a carriage which is movable by a motor. Another device, manufactured by Hamilton Equipment Company of Fort Worth, Tex., includes a concrete form vibrator for settling concrete in the form which uses inflatable bladders for forcing a pneumatic vibrator on a track against a concrete form The vibrator is typically moved manually in the track.
Other patented devices for use in forming concrete objects are disclosed in the following U.S. Patents, having the Ser. Nos. of: 1,540,901; 2,571,876; 2,853,250; 2,962,949; 3,200,177; 3,397,565; 3,530,552; 3,534,449; 3,604,324; 3,647,308; and 4,522,579.
Of the above devices, however, none is particularly adapted, as is a utility machine of the present invention, for the setting up of a concrete form, wherein the concrete form is cleaned, provided with tensioned strands which are depressed, and lubricated with form oil.
The present invention also includes a pouring machine for moving along the concrete form having means for continuously supplying concrete to the concrete form and means for continuously vibrating the concrete form as the pouring machine moves therealong. The pouring machine further includes a spreader and a compactor for spreading and compacting concrete into the concrete form as the pouring machine passes therealong.